During operation, a computing system consumes power from a power source. A mobile computing system may be designed to consume power from a portable and exhaustible power source, such as a battery. In order to prolong periods of mobile use, such a computing system may include elements designed to limit the amount of power consumed thereby.
These elements may include hardware and/or software for providing a low-power state during a period of relative inactivity. For example, a computing system might automatically enter a sleep state when not being used in order to reduce power consumption. Entering the sleep state may include reducing the brightness of a display, turning off a hard disk, and/or placing a processor in an idle state. As a result, energy can be conserved and/or battery life may be extended.
Some displays, such as Organic Light-Emitting Diode (OLED) displays, may be controlled such that one portion of a display consumes less power than other portions of the display. Conventional power-conserving techniques exploit this feature by displaying a user-selected window (or, alternatively, a window having “focus”) using a display method that is more power-consuming than the display method used to display other simultaneously-displayed windows.